* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

body {
    background: #333;
    text-align: center;
    padding-top: 40px;
}

h1 {
    color: #fff;
    font-size: 24px;
}

div.app {
    border: 1px solid #ddd;
    background: white;
    width: 300px;
    height: 200px;
    margin: 0 auto;
    margin-top: 30px;
    border-radius: 5px;
    padding: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.btn {
    width: 50px;
    height: 40px;
    padding: 5px 10px;
    border-radius: 10px;
}

.count {
    width: 50px;
    font-size: 24px;
}
